Naruto- Secret Sage

"You won't be able to save him like that. His very lifeforce has been damaged by the majority of the tailed beast being ripped out of him. The dregs of the beasts chakra are the only thing keeping him alive at the moment but those are rapidly burning up without the beast itself." I say seriously as his condition was plain to see for me.

"I know but I have to try." Chiyo said while she appeared to have aged even further in the short time since I last saw her. Where before she was old but spritely now she looked mere days from keeling over in weakness. 

In the end Gaara died despite all her effort and she sighed "It looks like there is a no choice but to use that technique." she said with a reluctant but determined look.

"He's dead and even his soul is starting to leave his body as it's vitality fails, nothing should be able to reverse this." I said confused.

"No there is something, a medical technique we at the sand developed in an attempt to copy the second Hokages forbidden technique, [Edo Tensei]. We considered the final result of that research a failure as while it can restore a recently dead person to life it cost the life of the caster." She said seriously.

"How recently dead?" I asked with narrowed eyes.

I knew of the forbidden technique she spoke of from reading the scroll of sealing. [Edo Tensei] was a highly imperfect technique developed by the second Hokage Tobirama Senju that pulled the souls of the dead from the pure lands back to the world of the living in immortal bodies with unending chakra prepared to house them under the casters control. The flaws however were just as dramatic as the effect.-

The first flaw was that the "resurrected" person had only a fraction of the strength they had when they were alive. This was why the second Hokage never focused on summoning powerful individuals but rather weak ones for suicidal and demoralizing tactics. His favorite tactic involved utilizing his other forbidden technique [Mutually multiplying explosive tags] which basically created a perpetual motion machine of explosive tags centered around the user which understandably meant their death. Anyway the second flaw was that in order to even use the technique you needed to have a living host for the soul to occupy.-

As the host body had to be the same species and general shape as the soul being summoned that meant people. The second Hokage used prisoners of war and death row inmates but the fact was it didn't matter beyond them being alive. The moment the summoning ended the host died as well since their soul had been forced out to make room for the new soul. To put it bluntly each use of the technique required the user to murder someone. This was why it was an extremely forbidden technique.-

The final real flaw with the technique was that in order to perform it you needed the DNA of whoever it was you were summoning which meant grave desecration more often then not. Besides these flaws however the technique did in fact bring the person back from the pure lands which was ironically how Konoha got a great deal of the jutsu that we possess currently. Those dead shinobi naturally knew everything about their jutsu and the second Hokage had used [Edo Tensei] to force that information out of them to be added to the library of Konoha.-

Compared to [Edo tensei] this new resurrection technique seemed far more promising as it traded the casters life for the one being revived in a true lasting resurrection.

"Within three hours of death. Any further and the soul will have already fully separated from the body and traveled to the pure lands." Chiyo said seriously.

"More useful for strong shinobi during war but otherwise not worth the trouble then." I said casually and she wasn't offended at all but nodded.

"We had similar thoughts once but only a skilled medical shinobi can utilize the technique and the cost to raise one was too great to utilize the technique for anyone who wasn't the Kazekage." she said and it was my turn to nod.

Trading a single skilled medical shinobi for another shinobi's life was a poor trade unless desperate or the shinobi being revived was vital to the village such as the Kazekage. That three hour rule though made nearly every possible shinobi it could be used on invalidated as a target since the likely hood of the body getting back to safety in that time after death is slim to none. That was assuming that there was enough left of the body to allow revival that is.-

When Chiyo started the technique I immediately understood WHY the swapping of lives was necessary. In her medical chakra that was flooding Gaara's body there was her own lifeforce having been mixed in. This caused the now fading lifeforce of Gaara's body to reignite as it started to draw in more and more of the foreign lifeforce to repair itself. To put it in simple terms the technique was literally trading ones life for the life of the revived. It wasn't a matter of the cost of the technique causing death from over draft but because when it finished the full lifeforce of the castor would be spent so death came naturally.-

As a positive note however Gaara's lifeforce that was rapidly recovering did so based on only itself rather than being intertwined with the tailed beast since he no longer held the thing. There was still parts of it that held the marks of the beast but the lifeforce fully belonged to Gaara now, clean and pure. It was only when the last wisps of chakra and lifeforce passed from Chiyo to Gaara did his lungs take in a new breath and his heart start to beat again while hers stopped.-

I watched as his soul settled back in his body while hers left her own, or rather that's what would have happened if I didn't intervein. I pressed my hand on her chest over her heart and sent a pulse of lifeforce through her that belonged to me. Immediately her lifeforce blazed back into existence and she drew in yet another breath as her heart continued beating.